Finned-tube heat exchanger

ABSTRACT

The present invention is related to an improved convector having a plurality of blades for heating, cooling as climatisation purposes and used with a thermal installation. This convector comprises a set of parallel blades fixed either on a covering pannel or on side plates and each blade comprises a central aperture intended to receive the pipe of a thermal installation. Important is the fact that each said aperture has a passage opening on one of the free edges of the blade, these passages being aligned, so that the convector, i.e. the assembly of blades and covering pannel or side plates can be assembled to the pipe by a movement perpendicular to the said pipe covering the passing of said pipe through the passages and its location within the central aperture of each blade. In order to obtain a good contact between the pipe and the blades, these blades are so formed that their central portion, in contact with the pipe have a built in self-resiliency tending to apply a portion of said blade against the pipe.

United States Patent [191 Stich 1 Nov. 12, 1974 1 1 FlNNED-TUBE HEATEXCHANGER [75] lnventor: Ernest Stich, Grand Laney-Geneva,

Switzerland [22] Filed: Feb. 14, 1973 [21} Appl. No.: 332,438

[301 Foreign Application Priority Data Feb. 15, 1972 Switzerland 2250/72Apr. 6, 1972 Switzerland 5080/72 July 27, 1972 Switzerland 11236/72 [52]US. Cl. 165/181, 29/157.3 B, 165/53, 165/55, 165/76, 165/129 [51] Int.Cl F281 l/3O [58] Field of Search 165/181, 182, 76, 53; 29/1573 A, 157.3B

[56] References Cited UNITED STATES PATENTS 672,412 4/1901 Birdsall165/181 1,925,720 9/1933 Haupt.... 165/182 2,089,340 8/1937 Cobb 165/1822,453,567 11/1948 Bronander 165/182 X 2,620,171 12/1952 Dubin et a1.165/182 3,249,156 5/1966 McGrew 165/181 FOREIGN PATENTS OR APPLlCATIONS316,887 4/1953 Switzerland 165/181 1,457,587 ll/l966 France 165/181Primary Examiner-Albert W. Davis, Jr. Assistant E.\aminerS. J. RichterAlmrney, Agent, or Firm-Young & Thompson [57] ABSTRACT The presentinvention is related to an improved convector having a plurality ofblades for heating, cooling as climatisation purposes and used with athermal installation. This convector comprises a set of parallel bladesfixed either on a covering pannel or on side plates and each bladecomprises a central aperture intended to receive the pipe of a thermalinstallation. Important is the fact that each said aperture has apassage opening on one of the free edges of the blade. these passagesbeing aligned, so that the convector. i.e. the assembly of blades andcovering pannel or side plates can be assembled to the pipe by amovement perpendicular to the said pipe covering the passing of saidpipe through the passages and its location within the central apertureof each blade. in order to obtain a good contact between the pipe andthe blades, these blades are so formed that their central portion, incontact with the pipe have a built in self-resiliency tending to apply aportion of said blade against the pipe.

5 Claims, 13 Drawing Figures ATENTEDXUV 12 IBM SHEET 1 OF 4 FINNED-TUBEHEAT EXCHANGER The present invention has for its object a convectorcomprising a finned-tube heat exchanger having blades mounted on a pipeintended to be connected to a thermal installation, either a heating orclimatisation installation or in a cooling circuit.

Such a heating or climatisation installation may equip for example anoffice building, a family house or even a vehicle. In the case of acooling circuit this can equip a car, the convector constituting aradiator to evacuate the calories.

The blades of the traditional convectors comprise a central aperture theperiphery of which present a cylindrical surface intended to enter incontact with the outside wall of the pipe which is passed through theaperture.

The conduction of the heat from the pipe towards the I mation of saidaperture, which causes a reduction of the contact surface of the bladewith the pipe and ,reduces the transmission of the calories towards theblade what causes a reduction in the efficiency of the convector.

One aim of the present invention is to remedy to this inconvience and toprovide for a convector comprising blades which remains in optimumcontact with the pipe on which they are mounted.

There exist blade convectors constituted by a tube on which blades areslid, generally ondulated blades, disposed parallely the ones with theother at some millimeter distance. These convectors are intended to beplaced in housings which are open on their top and on their bottom toconstitute a chimney permitting the circulation of air throughconvexion. Each convector has to be connected through nipples and avalve to the heating installation.

One of the object of the present invention is a convector certain bladesof which at least comprise means giving to the blade a resiliency on itsown tending to apply at least a portion of it against the outsidesurface of a pipe.

The invention has also for object a convector element to carry out theprocess described which distinguishes itself by the fact that itcomprises a covering pannel provided with a plurality of blades disposedparallely the ones with the others. Each blade has a cutting intended toreceive the piping of a heating installation.

The present invention has at least for its object a convector elementable to be fixed on a piping of the heating installation already set inplace which comprises a plurality of blades and which distinguishesitself by the fact that at least a part of these blades are embedded ina synthetical resine body so that these blades be maintained togetherapproximately parallel the one to the other and by the fact that eachblade comprises a cutting which opens on one of its free edges, thecuttings of all the blades being aligned and intended to receive apiping of a heating installation.

The attached drawing shows schematically and by way of example severalembodiments of the convector elements according to the invention.

FIG. 1 is a perspective view of a first embodiment of theconvector.

FIG. 2 is a transversal cross-section along line II-II of FIG. 1.

FIG. 3 is a front elevation view of a second embodi ment of theconvector.

FIG. 4 is a front elevation view of a third embodiment of the convector.

FIG. 5 is a partial cross-section seen in perspective of an otherembodiment of the convector.

FIG. 6 shows a detail of the convector shown on FIG. 5.

FIG. 7 shows in front view a convector of FIG. 5. FIG. 8 shows inperspective an other embodiment of the convector element which is setin'place on a piping of a heating.

FIG. 9 shows similar to FIG. 1, a further embodiment of the convectorelement.

FIG. 10 shows a front elevation of a last embodiment of the convector.

FIG. 11 shows in perspective and in longitudinal cross-section twoblades according to FIGS which are juxtaposed before being fixedtogether to the lateral plate.

FIG. 12 shows a cross-section along line VV of FIG. 8.

FIG. 13 is a view from above of the embodiment of the convector elementshown at FIG. 8.

In the drawing only the mounting of one or two blades on the piping ofthe convector has been shown at FIG. 1 to 4. It is evident that acomplete convector comprises a plurality of blades mounted on a samepiping and distant the one from the other of a few millimeters or of afew centimeters.

In the embodiment shown at FIG. 1 a blade 1 is in a heat conductingmaterial such as for example steel or aluminium plate.

This blade 1 comprises an upper plane 2 and a lower plane 3 making anangle a between them. These two planes are of general rectangular shapeand present same dimensions.

The blade 1 comprises further a cylindrical part 4 the axis of which islocated at the intersection point of the axis of symmetry of theblade 1. This cylindrical part 4 present an internal diameter whichcorresponds to the outside diameter of a piping 5 on which the blade 1is mounted by the sliding of this pipe through the cylindrical part 4.

One intends by corresponding diameter a diameter which is such that thepipe 5 may be introduced in the cylindrical portion 4 with slightfriction.

The blade 1 comprises further means which give to it a self resiliencytending to apply the internal surface of the cylindrical portion 4against the outside surface of the piping 5.

These means comprise a formation 6 either in recess or in projection,for example a rib formed in the other plane 2 which is obtained forexample by embossing and which extends along the vertical symmetry axisof the plane 2 from the upper edge of the blade (FIG. 1) up to thecylindrical part 4.

These means comprise further a notch 7 provided in the cylindrical part4, located in front of the formation 6 and a slot 8 provided in thelower plane 3 and which extends along this vertical symmetry axis of theplane 3 from the lower edge of the blade (FIG. 1) up to the cylindricalportion 4.

Referring to FIG. 2, one knows the flow of air represented by the arrowswhich passes through the convector and is influenced by the planes 2, 3of the blades and enters several times in contact with these planes. Dueto this fact, the efficiency of the blade is increased with respect tothe efficiency of a conventional blade which is disposed in a planeperpendicular to the piping 5. In fact, the air flowing thus through theconvector is heated at several times before it leaves the convector.

In a variant of this first embodiment, the upper plane 2 and the lowerplane 3 comprise each a formation 6 extending along the verticalsymmetry axis of the blade 1. The cylindrical portion 4 comprises twonotches 7, each of them being provided in front of a formation 6.

The two formations 6 and the two notches 7 give to the blade a selfresiliency tending to apply the cylindrical portion 4 against theoutside surface of the piping 5.

In a second variant, the means giving to the blade a self-resiliencycomprises a notch 7 provided in the cylindrical portion 4 and aformation 6 provided in the upper plane. 2 such as described previously.These means comprise further a slot provided in the lower plane 3 whichextends along the vertical symmetry axis of the plane 3 from thecylindrical portion 4 in direction of the lower edge of the plane, on apart of the vertical symmetry axis.

In a second embodiment shown at FIG. 3, a blade 9 comprises only oneplane and has a general square shape. This blade 9 comprises acylindrical portion 10 the axis of which is perpendicular to the planeof the blade 9 which presents an inside diameter corresponding to theoutside diameter of the piping on which the blade is mounted.

Means giving to the blade a self resiliency tending to apply theinternal surface on the cylindrical portion against the outsidesurfaceof the piping 5 comprise a circular groove 11 concentrical to thecylindrical portion 10 and connected to its through four radial ribs 12disposed for example each along one of the diagonal of the blade 9. v

These means comprise further four notches 13 provided in the cylindricalportion 10 at the jonction of each radial rib 12 with said cylindricalportion 10.

In variants of this second embodiment the number of radial ribs 12 maybe different for example 2, 3 or greater than 4. In an other variant themeans giving a self resiliency to the blade could comprise only thecircular groove 11 and a certain number of notches 13 at least one.

In a third embodiment shown at FIG. 4 a blade 14 comprises only oneplane of general square shape and provided with a cylindrical portion 15perpendicular to the plane of the blade 14.

The inside diameter of this cylindrical portion 15 corresponds to theoutside diameter of the piping 5 on which the blade is mounted.

The means giving to the blade a self resiliency tending to apply theinside surface of the cylindrical portion 15 against the outside surfaceof the piping 5 comprises four rectilinear ribs 16 extending each alongone of the diagonals of the blade 14 in connecting a corner of the bladeto the cylindrical portion 15.

These means comprise further four notches 17 provided on the cylindricalportion R5 at the junction of a rectilinear rib 16 with this cylindricalportion 15.

In a variant, a plurality of notches 17 is provided on the cylindricalportion 15 around the periphery in order to constitute a plurality ofadjacent cylindrical portions.

One cylindrical portion is fold out of the plane of the blade on oneside of it whereas the other adjacent cylindrical portions are foldedoutside of the plane of the blade on the other side of it. In thisvariant the adjacent cylindrical portions extend on either side of theplane of the blade.

Finally in an other variant the means giving to the blade itself-resiliency tending to ensure a good thermal contact between theblade and the piping on which it is mounted may be constituted only by aplurality of cylindrical portions such as 15, separated by notches suchas 17. In this case however it may be necessary to give at the foldingor the embossing of these cylindrical portions a certain inclinasion ofthem in direction of the axis of the piping 5. In this manner when theblades are sliped on the piping 5 these cylindrical portions areelastically deformed against their self-resiliency.

It is evident that in a variant of the embodiment shown at FIGS. 3 and 4one may use a blade presenting two planes making an angle between themsuch as described in the first embodiment.

It is the same for the first embodiment shown at FIG. 1 which in avariant could comprise blades presenting only one plane perpendicular tothe piping 5 or inclined with respect to this piping.

Thanks to the different means used to givea selfresiliency to the bladesone obtains always the same result, a stress of the cylindrical portionof the blade, surrounding the pipe against its self-resiliency tendingto apply it against this piping. In this way one always realizes,whatever the temperature or the difference of the thermal dilatationcoefficients between the blades and the piping are an excellent thermalconduction between these elements which garanties an optimal efficiencyof the convector.

According to the present invention it is possible to suppress all themounting work, of connecting and so on of the classic convectors. As amatter of fact, with reference to the FIGS. 5 to 7, during the framework of a building the pipes 1a (FIGS. 5 to 7) of a heating installationare laid.

To be noted however that these pipings are not interrupted at the placeswhere it will be necessary to provide convectors. One obtains thus aminimum of fittings which enables a much quicker work and suppresses theleak possibilities.

On the other hand one prepare on the workshop the convector elementsconstituted by a covering pannel 2a on which the blades 3a are fixed.These blades are glued, soldered or fixed in any other way to the rearface of this covering plates 2a. The blades are disposed parallely theones to the other at some millimeter distance. The plates occupy thelower portion of the rear face of the plate 2a.

The pannels 20 may be provided with perforations (not shown) and/or withan insulating layer 4a in their upper portion in order to act as phonicinsulating element.

Each blade is provided with a cutting 5a opening in the example shown onthe lower edge of the blade. This 1 portion of the heating piping la,already laid, in the cuttings of the blades 3a.

This method is extremely flexible since it is possible to dispose sideby side as many convector elements as is necessary to obtain the desiredcalories for a given volume.

In the examples shown at FIGS. 5 to 7 the upper portion of the convectoris terminated by a combined board fastened into the wall. This boardcomprises a window flange 6a and a board 7a provided with openings 8a togive passage to the hot air. A joint 9a connect the forward edge of thisboard 7a to the upper edge of the pannel 2a. Of course the lateral endsof the convector thus realized may be obtained by prefabricated walls toincrease the efficiency of the convector.

For aesthetic reasons one may provide pannels 2a which do not compriseblades.

The console shown comprises further an obturation plate a forming aclosed housing Ila in which electrical ducts may be laid.

It is evident that the openings 8a of the board 7a may be obturated moreor less in order to regulate the hot air quantity delivered to thevolume in which the convector is mounted.

It is possible, to provide for a good fitting of the blade 3a againstthe pipe la, and to give a good thermal conduction to provide for amember 12a the ends of which are introduced in slots of the blades andtenting to close the cutting 5a and to clamp the pipe 1a. One mayprovide one element for each blade or on the contrary one element for acomplete convector. In this later case the element would be providedwith openings in order to oppose only a low resistance to the air flow.

FIG. 6 shows a variant in which the edge of the cutting of the blades 3aentering in contact with the piping la is actually off set. It is thuspossible to apply this edge 13a through its self-resiliency stronglyagainst the piping la.

' In a variant, a movable flap is fixed to the element 12 in order to beable to regulate the air circulation in order to control the ambianttemperature of the room.

In the embodiment shown at FIGS. 8 and 11 to 13, the convector elementcomprises a plurality of blades lb two opposed edges of which areembedded in lateral plates 2b in synthetic material. The blades extendapproximatively parallel the one to the other and are rigidly maintainedtogether by the lateral plates. As shown at FIG. 11, the edge of theblades lb which is embedded in the lateral plates 2b shows an anchoringformation 3b to provide for a good anchoring of the blade into theplates 3b.

Each of the blades lb presents a cutting 4b intended to give passage toa tubing 5b, of a heating installation. These cuttings are aligned andpresent all an opening towards a free edge 6b of their blade lb. Thus itis possible once the convector element is terminated, that is the bladesassembled by the lateral plates to introduce a heating piping through adisplacement of the element perpendicularly to this heating piping, intothe cutting of each blade of the element and to constitute thus aheating body or convector.

Taking reference to FIGS. 11 and 12 more particularly one sees that thecutting 4b is constituted by a deformation of the central portion of theblade. This deformation is such said a skirt 7b surrounds a portion ofthe cutting and is connected to the rest of the blade through a fold 8b.Slots 9b are provided in this skirt 7b.

In this manner, one ensures a good heat transmission from the piping 5btowards the blades 1b. In fact, the contact surface between this bladesand the piping is greatly increased and the self-resiliency of the skirtapplies in service position this skirt firmly against the said pipe. Inorder to obtain this, one provides during the manufacture for the insidediameter of the skirt 7b to be slightly less than the outside diameterof the piping 5b on which the convector element has to be fixed.

Finally, in order to permit an identical distance between the blades,each of them comprises a flap 10b folded in a plane parallel to thelongitudinal axis of the convector element. This flap has two functions.Firstly a spacing function, the frontal edge of the flap of one bladecoming in abutment against the face of the adjacent blade. Then anaerodynamic function when the convector element is in service. In fact,the convector obtained by the piping 5b and the element described isgenerally located against a wall, so that the air crossing the convectoris sucked by only one of its side according to the arrow f. In order toobtain a good repartition of the air flowing in the convector, it isnecessary to reject towards the front a part of this currentfwhichotherwise would circulate mainly in the rear part of the convector.Thanks to the flaps 10b, this effect is obtained.

In the embodiment shown at FIG. 9, the convector is composed of thepiping 5b of the heating installation and of two convector elementsmaintained in place on the piping 5b, by fixing members, screws 11b inthe example shown.

Each convector element comprises blades 12b one edge of which, providedwith anchoring members, is embedded in a lateral plate 13b in mouldedsynthetic material.

The cutting provided in each blade opens on the edge of the bladeopposed to the one which is embedded in the plate 13b and presents ageneral semi-circular shape. As in the preceding embodiment, thiscutting may be defined by a skirt obtained through a fold 14b providedin the blade 12]).

Each convector element of this embodiment constitute in fact half aconvector.

Each blade 12b may also comprise a spacing flap as in the embodimentshown at FIGS. 8 and 11' to 13.

The embodiment shown at FIG. 10 comprises also elements constitutinghalf a convector, the blades 15b presenting a general triangular shape.Each of these blades 15b is also fastended with a lateral plate 16b andpresent a fold 17b constituting a skirt defining the cutting which openson the edge of the blade forming an angle with the blade 16b.

In order to fix two convector elements around a piping 5b springs 18bare provided. These springs may be fixed either as illustrated on theblades or on the plates 16b.

In a variant which is not shown, the covering plates of a convector maybe constituted by a lateral plate 2b, 13b or 16b.

I claim:

l. A finned-tube heat exchanger comprising a cylindrical conduit and aplurality of thin metal fins spaced apart along the conduit in heatexchange relation therewith, each said fin having a cylindrical collarthat bears resiliently against the conduit, each fin being in the formof a dihedral disposed in two planes, the fin having a corrugationtherein extending from said cylindrical collar to the edge of the fin,the fin also having a slot therein extending from said cylindricalcollar to the edge of said fin, said slot and said corrugation beingperpendicular to the intersection of said planes.

LII

notch in said collar at the base of said corrugation.

1. A finned-tube heat exchanger comprising a cylindrical conduit and aplurality of thin metal fins spaced apart along the conduit in heatexchange relation therewith, each said fin having a cylindrical collarthat bears resiliently against the conduit, each fin being in the formof a dihedral disposed in two planes, the fin having a corrugationtherein extending from said cylindrical collar to the edge of the fin,the fin also having a slot therein extending from said cylindricalcollar to the edge of said fin, said slot and said corrugation beingperpendicular to the intersection of said planes.
 2. A heat exchanger asclaimed in claim 1, the cylindrical collar having a notch therein.
 3. Aheat exchanger as claimed in claim 1, said corrugation and slot beingstraight.
 4. A heat exchanger as claimed in claim 1, said corrugationand slot being disposed on opposite sides of said collar.
 5. A heatexchanger as claimed in claim 4, and a notch in said collar at the baseof said corrugation.